<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8" />
		<title>盒子模型</title>
		<link href="css/box.css" rel="stylesheet"/>
	</head>
	<body>
		<!--
		盒子模型4个元素：
		1.content内容
		2.padding内边距
		3.border边框
		4.margin外边距 
		-->
		<div class="box1">hello world</div>
	</body>
</html>
